摘要 |
<p>Activated sludge is biologically converted into a form in which it is readily concentrated by conventional means. The method of concentration comprises adding to the sludge oxygen-containing nitrogen compounds, most suitably nitrates or nitrites, in an amount of 50 to 1000 g/m<3> under anaerobic conditions so as to form sludge flakes with an altered physical structure, formed by enzyme activity, which are directly concentrated.</p> |